Wireless communication systems are distinguished over fixed communication systems, such as the public switched telephone networks (PSTN), principally in that subscriber units move between communication service areas and providers and in doing so encounter varying radio propagation environments. Therefore the quality of a communication link to/from a subscriber unit varies as the subscriber unit changes location. The subscriber units are typically either vehicular-mounted ‘mobile’ or ‘hand-portable’ radio or cellular units. Henceforth, the term mobile station (MS) will be used for all such subscriber units. Wireless communication systems, for example cellular telephony or private mobile radio communication systems, typically provide for radio telecommunication links to be arranged between a plurality of subscriber units.
In a private mobile radio (PMR) wireless communication system, there are typically two methods of communicating. A first communication method is a direct communication between two MSs. A second method uses one or more intermediary stations to forward the communication to a MS. The intermediary station may be a base transceiver station (BTS) connected to the communication system infrastructure. A BTS is generally considered an “intelligent” terminal, as it has the processing and control capability to influence a substantial amount of the communication traffic passing through it.
A further intermediary station is a radio repeater station, which performs a minimal amount of processing in receiving a communication and re-transmitting the received communication along the wireless communication path. As a repeater station has little control over the communication passing through it, it is often termed a “dummy” terminal.
Buildings, such as multi-story office blocks, warehouses and factories present particular problems for emergency personnel responding to a call. These problems include poor communications inside the building between the emergency team members and their supervisors, keeping track of the location of personnel inside the building, and navigating in the building under adverse conditions, such as fire or dense smoke.
A wide range of equipment has been used in the past, to facilitate communication in such adverse conditions both in fixed installations in buildings and as portable equipment brought in by the emergency services. Fixed equipment includes emergency telephones as an integral part of the fire alarm system, warden and stand pipe phones, Emergency Announcement systems, and radio repeater systems. Portable equipment includes both cellular phones, dedicated (Private) cellular networks such as iDEN™, and Handie-Talkie (HT) communication radios, such as the Motorola™ analog VHF 154 MHz Saber 1/1E or the digital UHF 800 MHz XTS 3500, and portable repeaters.
However, it has been found that under severe disaster conditions, such as terrorist attack or earthquakes, the building infrastructure may be damaged to such an extent that most if not all of these systems are either damaged beyond use, or become ineffective due to traffic overload.
For this reason, there has been significant research in recent years on systems to allow tracking and location of emergency personnel. In certain environments, use is made of Personal Location Beacons (PLB's) and Emergency Location Beacons (ELB's). These use a satellite tracking network which receives an emergency transmission at either 121.5 MHz or 406 MHz and automatically notifies the beacon's location. They have, however, been found to be ineffective in a closed/building environment.
Thus, a need exists for an improved wireless communication system, associated portable radio repeater and portable magazine therefor.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.